Suspension element

ABSTRACT

A suspension element includes a main body having an internal volume configured to contain a liquid therein, a tubular element extending at least partially within the main body, the tubular element having an internal volume that defines a first fluid chamber configured to contain a compressible gas therein, a first piston separating the internal volume of the main body into a second fluid chamber and a third fluid chamber, a second piston positioned to separate the first fluid chamber from the second fluid chamber, and a flow control element disposed along a flow path between the second fluid chamber and the third fluid chamber. Movement of the tubular element generates a flow of the liquid through the flow control element to produce a damping force and changes the pressure of the compressible gas to produce a spring force.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/684,082, filed Apr. 10, 2015, which claims the benefit of U.S.Provisional Application No. 61/978,624, filed Apr. 11, 2014, both ofwhich are incorporated herein by reference in their entireties.

BACKGROUND

Suspension systems traditionally couple a body of a vehicle to one ormore axles. Such suspension systems may include solid axle suspensionsystems or independent suspension systems, among others. Independentsuspension systems facilitate independent wheel movement as the vehicleencounters one or more obstacles (e.g., uneven terrain, potholes, curbs,etc.). The independent suspension system reduces the forces experiencedby passengers as the vehicle encounters the obstacles. Independentsuspension systems include one or more arms (e.g., A-arms, swing arms,etc.) that are coupled to a hub, to which a wheel and tire assembly isattached. Various suspension components are coupled to the arms and thebody of the vehicle.

SUMMARY

One embodiment relates to a suspension element that includes a main bodyhaving an internal volume configured to contain a liquid therein, atubular element extending at least partially within the main body, thetubular element having an internal volume that defines a first fluidchamber configured to contain a compressible gas therein, a first pistonseparating the internal volume of the main body into a second fluidchamber and a third fluid chamber, a second piston positioned toseparate the first fluid chamber from the second fluid chamber, and aflow control element disposed along a flow path between the second fluidchamber and the third fluid chamber. Movement of the tubular elementgenerates a flow of the liquid through the flow control element toproduce a damping force and changes the pressure of the compressible gasto produce a spring force.

Another embodiment relates to a suspension element that includes a mainbody having an internal volume configured to contain a liquid therein, atubular element having an internal volume that defines a first fluidchamber configured to contain a compressible gas therein, a first pistonseparating the internal volume of the main body into a second fluidchamber and a third fluid chamber, a second piston separating the firstfluid chamber from the second fluid chamber, a flow control elementdisposed along a flow path between the second fluid chamber and thethird fluid chamber, and a ride height sensor positioned to monitor anorientation of the tubular element relative to the main body.

Still another embodiment relates to a suspension system for a vehiclethat includes a first suspension element and a second suspensionelement. Each of the first suspension element and the second suspensionelement include a main body having an internal volume configured tocontain a liquid therein, a tubular element extending at least partiallywithin the main body, the tubular element having an internal volume thatdefines a first fluid chamber configured to contain a compressible gastherein, a first piston separating the internal volume of the main bodyinto a second fluid chamber and a third fluid chamber, a second pistonpositioned to separate the first fluid chamber from the second fluidchamber, and a flow control element.

The invention is capable of other embodiments and of being carried outin various ways. Alternative exemplary embodiments relate to otherfeatures and combinations of features as may be recited in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will become more fully understood from the followingdetailed description, taken in conjunction with the accompanyingfigures, in which:

FIGS. 1-2 are perspective views of axle assemblies, according toalternative embodiments;

FIG. 3A is a side view of a suspension element, according to anexemplary embodiment;

FIG. 3B is a sectional view of the suspension element of FIG. 3A;

FIG. 4 is a sectional view of a suspension element, according to analternative embodiment;

FIG. 5 is side view of a suspension element, according to an alternativeembodiment;

FIG. 6 is a sectional view of the suspension element of FIG. 5;

FIG. 7 is an exploded view of the suspension element of FIG. 5;

FIG. 8A is a side view of a suspension element, according to analternative embodiment;

FIG. 8B a sectional view of the suspension element of FIG. 8A;

FIG. 9A is a side view of a suspension element, according to analternative embodiment;

FIG. 9B is a sectional view of the suspension element of FIG. 9A;

FIG. 10A is a side view of a suspension element, according to analternative embodiment;

FIG. 10B is a sectional view of the suspension element of FIG. 10A;

FIG. 11A is a side view of an suspension element, according to analternative embodiment;

FIG. 11B is a sectional view of the suspension element of FIG. 11A;

FIG. 12A is a side view of an suspension element, according to analternative embodiment;

FIG. 12B is a top view of the suspension element of FIG. 12A;

FIG. 12C is a sectional view of the suspension element of FIG. 12A;

FIG. 12D is a detail view of an upper mount of the suspension element ofFIG. 12C;

FIG. 12E is sectional view of the suspension element of FIG. 12B;

FIG. 12F is another sectional view of the suspension element of FIG.12B;

FIG. 13A is a side view of an suspension element, according to analternative embodiment;

FIG. 13B is a top view of the suspension element of FIG. 13A;

FIG. 13C is a sectional view of the suspension element of FIG. 13A;

FIG. 13D is a detail view of an upper mount of the suspension element ofFIG. 13C;

FIG. 13E is sectional view of the suspension element of FIG. 13B; and

FIG. 13F is another sectional view of the suspension element of FIG.13B.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate the exemplaryembodiments in detail, it should be understood that the presentapplication is not limited to the details or methodology set forth inthe description or illustrated in the figures. It should also beunderstood that the terminology is for the purpose of description onlyand should not be regarded as limiting.

According to an exemplary embodiment, a vehicle may include a bodysupported by a suspension system. In some embodiments, the vehicle is amilitary vehicle. In other embodiments, the vehicle is a utilityvehicle, such as a fire truck, a tractor, construction equipment, or asport utility vehicle. The vehicle may be configured for operation onboth paved and rough, off-road terrain. As such, the suspension systemmay be correspondingly configured to support the weight of the vehiclewhile providing comfortable ride quality on both paved and rough,off-road terrain. In some embodiments, the suspension system isconfigured to change the ride height of the vehicle by lifting orlowering the body of the vehicle with respect to the ground.

Referring to FIGS. 1-2, an axle assembly is configured for use with thevehicle. According to the exemplary embodiment shown in FIG. 1, an axleassembly 10 includes a differential 12 connected to half shafts 14,which are each connected to a wheel end assembly 16. As shown in FIG. 2,wheel end assembly 16 is not connected to a differential 12 by a halfshaft 14. As shown in FIGS. 1-2, the wheel end assembly 16 is at leastpartially controlled (e.g., supported) by a suspension system 18, whichincludes a suspension element, shown as integrated spring damper 20, anupper support arm 24, and a lower support arm 26 coupling the wheel endassembly 16 to the vehicle body or part thereof (e.g., chassis, sideplate, hull, etc.). As shown in FIGS. 1-2, suspension system 18including integrated spring damper 20 may be implemented on a drivenaxle or a non-driven axle of a vehicle (e.g., an axle that includes ordoes not include a differential, half shaft, drive motor, or othercomponent configured to provide a motive force, etc.).

According to an exemplary embodiment, the differential 12 is configuredto be connected with a drive shaft of the vehicle, receiving rotationalenergy from a prime mover of the vehicle, such as a diesel engine. Thedifferential 12 allocates torque provided by the prime mover betweenhalf shafts 14 of the axle assembly 10. The half shafts 14 deliver therotational energy to the wheel end assemblies 16 of the axle assembly10. The wheel end assemblies 16 may include brakes (e.g., disc brakes,drum brakes, etc.), gear reductions, steering components, wheel hubs,wheels, and other features. As shown in FIG. 2, the wheel end assemblies16 include disc brakes. As the vehicle travels over uneven terrain, theupper and lower support arms 24, 26 at least partially guide themovement of each wheel end assembly 16, and a stopper 28 provides anupper bound for movement of the wheel end assembly 16.

The integrated spring damper 20 is configured to provide both thefunctionality of a gas spring and the damping functionality of ahydraulic damper. The integrated spring damper 20 allows the ride heightof the suspension to be raised or lowered (e.g., a kneel function). Theintegrated spring damper 20 is smaller and a more robust package than atypical gas spring. The integrated spring damper 20 also utilizes lesshydraulic fluid than traditional dampers, provides increased dampingcontrol, and offers increased service life.

According to the exemplary embodiment shown in FIGS. 3A-3B, anintegrated spring damper 100 is configured to act as a damper (e.g., ahydraulic damper) and a spring (e.g., a high pressure gas spring). Theintegrated spring damper 100 includes a main body 102 (e.g., cylinder,housing, base, etc.). In one embodiment, main body 102 is tubular. Theends of the main body 102 are closed by a cap 104 and a barrier 106 todefine an internal volume. The internal volume of the main body 102 isseparated into a central chamber and an annular, outer chamber by aninner tube 110 that extends from the cap 104 to the barrier 106. The endof the inner tube 110 proximate to the barrier 106 is closed with a cap112. The cap 112 may be generally aligned with the barrier 106 (e.g.,received in a central opening 114 in the barrier 106). The integratedspring damper 100 further includes a tubular (e.g., cylindrical, etc.)second body, shown as main tube 116. In one embodiment, main tube 116 istubular and defines an inner volume. The main tube 116 is received inthe annular chamber of the internal volume of the main body 102. Themain tube 116 is configured to translate with respect to the main body102. According to an exemplary embodiment, the main tube 116 has aninner diameter that is approximately equal to the outer diameter of theinner tube 110 such that the inner tube 110 is received in the main tube116 when the main tube 116 is disposed within the internal volume of themain body 102. The distal end of the main tube 116 is closed by a cap118. The cap 104, barrier 106, cap 112, and cap 118 may be coupled tothe respective components with a threaded connection or with anothercoupling mechanism (e.g., welding, brazing, interference fit, etc.).

According to an exemplary embodiment, the integrated spring damper 100includes a first eyelet 120 and a second eyelet 122 with which theintegrated spring damper 100 is coupled to an axle assembly. Accordingto an exemplary embodiment, the integrated spring damper 100 is coupledon one end (e.g., via the first eyelet 120) to a moveable member of theaxle assembly (e.g., an upper support arm, a lower support arm, etc.)and on the other end (e.g., via the second eyelet 122) to the vehiclebody or part thereof (e.g., chassis, side plate, hull). According to anexemplary embodiment, the first eyelet 120 and the second eyelet areintegrally formed with the cap 104 and the cap 118, respectively.

A main piston 124 is disposed in the outer annular chamber definedbetween the main body 102 and the inner tube 110. The main piston 124 iscoupled to the main tube 116 and extends to an inner surface of the mainbody 102. The main piston 124 separates the outer annular chamber intofirst annular chamber 126 and a second annular chamber 128. When themain tube 116 translates relative to the main body 102, the main piston124 changes the volume of the first annular chamber 126 and the secondannular chamber 128. A dividing piston 130 (e.g., floating piston) isdisposed in the inner chamber defined by the inner tube 110. Thedividing piston 130 slidably engages the inner tube 110. The dividingpiston 130 separates the inner chamber into first inner chamber 132 anda second inner chamber 134. The pistons 124 and 130 may be coupled tothe sidewalls of the main body 102 and the inner tube 110 with a seal orother interfacing member (e.g., ring, wear band, guide ring, wear ring,etc.).

The first annular chamber 126, the second annular chamber 128, and thefirst inner chamber 132 contain a generally non-compressible fluid. Inone embodiment, the first annular chamber 126, the second annularchamber 128, and the first inner chamber 132 are hydraulic chambersconfigured to contain a hydraulic fluid therein (e.g., water, hydraulicoil, etc.). The first inner chamber 132 is in fluid communication withthe first annular chamber 126 through apertures 136 in the inner tube110. The fluid may flow between the first annular chamber 126 and thesecond annular chamber 128 through a passage 142 (e.g., conduit, bore,etc.) in a bypass manifold 140. According to an exemplary embodiment,the bypass manifold 140 is a structure coupled (e.g., bolted) to theside of the main body 102 and the passage 142 is in fluid communicationwith the first annular chamber 126 through an aperture 144 in the mainbody 102 and with the second annular chamber 128 through an aperture 146in the main body 102. Providing the bypass manifold 140 as a separatecomponent coupled to the exterior of the main body 102 allows the bypassmanifold 140 to be replaced to vary the behavior of the integratedspring damper 100, such as by changing the valving or adding optionalfeatures (e.g., position dependency).

The flow of fluid through the passage 142 is controlled by a flowcontrol device 148. According to an exemplary embodiment, the flowcontrol device 148 is a disk valve disposed within the bypass manifold140 along the passage 142. In other embodiments, the flow control device148 may be another device, such as a pop off valve, or an orifice. Inother embodiments, the flow control device remotely positioned but influid communication with the first annular chamber 126 and the secondannular chamber 128.

The second inner chamber 134 contains a generally compressible fluidthat may include (e.g., at least 90%, at least 95%) an inert gas such asnitrogen, argon, or helium, among others. The second inner chamber 134is in fluid communication with the internal volume 150 of the main tube116 through apertures 152 in the cap 112. In some embodiments, theinternal volume 150 of the main tube 116 is in fluid communication withexternal devices, such as one or more reservoirs (e.g., centralreservoir, tank), an accumulator, or device allowing the pressure of thegas to be adjusted. The pressure of the gas may be adjusted by removingor adding a volume of gas to adjust the suspension ride height.

When the integrated spring damper 100 is compressed or extended, themain tube 116 translates relative to the main body 102. The gas held inthe second inner chamber 134 compresses or expands in response torelative movement between the main tube 116 and the dividing piston 130,which may remain relatively stationary but transmit pressure variationsbetween the incompressible hydraulic fluid in the first inner chamber132 and the compressible fluid in second inner chamber 134. The gas inthe second inner chamber 134 resists compression, providing a force thatis a function of the compressibility of the gas, the area of the piston,the volume and geometry of the chamber, and the current state (e.g.,initial pressure) of the gas, among other factors. The receipt ofpotential energy as the gas is compressed, storage of potential energy,and release of potential energy as the gas expands provide a springfunction for the integrated spring damper 100.

Movement of the main tube 116 relative to the main body 102 translatesthe main piston 124, causing the volume of the first annular chamber 126and the second annular chamber 128 to vary. When the integrated springdamper 100 compresses, the volume of the first annular chamber 126decreases while the volume of the second annular chamber 128 increases.The fluid is forced from the first annular chamber 126 through thepassage 142 and past the flow control device 148 into the second annularchamber 128. The resistance to the flow of the fluid through the passageprovides a damping function for the integrated spring damper 100 that isindependent of the spring function. Movement of the main piston 124 alsochanges the pressure of the fluid within first inner chamber 132. Suchpressure variation imparts a force on a first side of the dividingpiston 130 that varies the pressure of the fluid within the second innerchamber 134.

Referring to FIG. 4, an integrated spring damper 200 is shown, accordingto another exemplary embodiment. The integrated spring damper 200includes a tubular (e.g., cylindrical, etc.) main body 202 (e.g.,cylinder, housing, base, etc.). The ends of the main body 202 are closedby a cap 204 and a barrier 206 to define an internal volume. Theintegrated spring damper 200 further includes a tubular (e.g.,cylindrical, etc.) main tube 216. The main tube 216 is received in theinternal volume of the main body 202. The main tube 216 is configured totranslate with respect to the main body 202. The distal end of the maintube 216 is closed by a cap 218. The cap 204, barrier 206, and cap 218may be coupled to the respective components with a threaded connectionor with another coupling mechanism (e.g., welding, brazing, interferencefit, etc.).

According to an exemplary embodiment, the integrated spring damper 200includes a first eyelet 220 and a second eyelet 222 with which theintegrated spring damper 200 is coupled to an axle assembly. Accordingto an exemplary embodiment, the integrated spring damper 200 is coupledon one end (e.g., via the first eyelet 220) to a moveable member of theaxle assembly (e.g., an upper support arm, a lower support arm, etc.)and on the other end (e.g., via the second eyelet 222) to the vehiclebody or part thereof (e.g., chassis, side plate, hull). According to anexemplary embodiment, the first eyelet 220 and the second eyelet 222 areintegrally formed with the cap 204 and the cap 218, respectively.

A main piston 224 is disposed in the internal volume of the main body202. The main piston 224 is coupled to the main tube 216 and slidablyengages the main body 202. The main piston 224 separates the internalvolume into a first chamber 226 (e.g., compression chamber) and a secondchamber 228 (e.g., extension chamber). The first chamber 226 is agenerally cylindrical chamber comprising the portion of the internalvolume of the main body 202 between the main piston 224 and the cap 204.The second chamber 228 is an annular chamber defined between the mainbody 202 and the main tube 216 and extends between the main piston 224and the barrier 206. When the main tube 216 translates relative to themain body 202, the main piston 224 changes the volume of the firstchamber 226 and the second chamber 228. A dividing piston 230 (e.g.,floating piston) is disposed in the main tube 216 and slidably engagesthe main tube 216. The dividing piston 230 separates the internal volumeof the main tube 216 into the first inner chamber 232 and a second innerchamber 234. According to an exemplary embodiment, the first innerchamber 232 is open to (i.e., in fluid communication with) the firstchamber 226.

A limiter, shown as recoil damper 236, is disposed within the internalvolume of the main body 202 between the main piston 224 and the barrier206. The recoil damper 236 is intended to reduce the risk of damage tothe main piston 224, barrier 206, the sidewall of main body 202, orstill another component of integrated spring damper 200 by reducing theforces imparted by the main piston 224 as it travels toward an end ofstroke. According to an exemplary embodiment, the recoil damper 236includes a recoil piston 238 positioned within the second chamber 228and a resilient member such as an interlaced wave spring (i.e., a flatwire compression spring), a coil spring, or another type of spring. Theresilient member may be disposed between the recoil piston 238 and thebarrier 206. According to an exemplary embodiment, the resilient memberis not intended to damp the movement of the main piston 224 butpositions the recoil piston 238 within the main body 202, such as afterit has been displaced by the main piston 224. In other embodiments, therecoil damper 236 may not include a resilient member and the recoilpiston 238 may be repositioned using gravity or an alternative device.

Occupants within a vehicle experience large impulse forces as the mainpiston 224 contacts the barrier 206 or a component of the suspensionsystem engages a hard stop. The recoil damper 236 reduces such impulseforces transmitted to occupants within the vehicle by dissipating aportion of the kinetic energy of the main piston 224 and the main tube216 (i.e. provide a supplemental damping force) as the integrated springdamper 200 reaches an end of stroke (e.g., as the piston reaches arecoil end of stroke, as the piston reaches a jounce end of stroke,etc.).

The first chamber 226, the second chamber 228, and the first innerchamber 232 contain a generally non-compressible fluid (e.g., hydraulicfluid, oil, etc.). The first inner chamber 232 is in fluid communicationwith the first chamber 226 through an opening 225 in the main piston224. The fluid may flow between the first chamber 226 and the secondchamber 228 through a passage 242 (e.g., conduit, bore, etc.) in abypass manifold 240. According to an exemplary embodiment, the bypassmanifold 240 is a structure coupled to the side of the main body 202.The passage 242 is in fluid communication with the first chamber 226through an aperture 244 in the main body 202 and with the second chamber228 through an aperture 246 in the main body 202. According to anexemplary embodiment, the aperture 246 opens into the second chamber 228between the main piston 224 and the recoil piston 238. The flow of fluidthrough the passage 242 is controlled by a flow control device 248.According to an exemplary embodiment, the flow control device 248 is adisk valve disposed within the bypass manifold 240 along the passage242. In other embodiments, the flow control device 248 may be anotherdevice, such as a pop off valve, or an orifice. In other embodiments,the flow control device remotely positioned but in fluid communicationwith the first chamber 226 and the second chamber 228.

The second inner chamber 234 contains a generally compressible fluidthat may include (e.g., at least 90%, at least 95%) an inert gas such asnitrogen, argon, or helium, among others. In some embodiments, thesecond inner chamber 234 is in fluid communication with externaldevices, such as one or more reservoirs (e.g., central reservoir, tank),an accumulator, or device allowing the pressure of the gas to beadjusted. The pressure of the gas may be adjusted by removing or addinga volume of gas to adjust the suspension ride height.

When the integrated spring damper 200 is compressed or extended, themain tube 216 translates relative to the main body 202. The gas held inthe second inner chamber 234 compresses or expands in response torelative movement between the main tube 216 and the dividing piston 230,which may remain relatively stationary but transmit pressure variationsbetween the incompressible hydraulic fluid in the first inner chamber232 and the compressible fluid in second inner chamber 234. The gas inthe second inner chamber 234 resists compression, providing a force thatis a function of the compressibility of the gas, the area of the piston,the volume and geometry of the chamber, and the current state (e.g.,initial pressure) of the gas, among other factors. The receipt ofpotential energy as the gas is compressed, storage of potential energy,and release of potential energy as the gas expands provide a springfunction for the integrated spring damper 200.

Movement of the main tube 216 relative to the main body 202 translatesthe main piston 224, causing the volume of the first chamber 226 and thesecond chamber 228 to vary. When the integrated spring damper 200compresses, the volume of the first chamber 226 decreases while thevolume of the second chamber 228 increases. The fluid is forced from thefirst chamber 226 through the passage 242 and past the flow controldevice 248 into the second chamber 228. The resistance to the flow ofthe fluid through the passage 242 provides a damping function for theintegrated spring damper 200 that is independent of the spring function.

Referring to FIGS. 5-7, an integrated spring damper 300 is shown,according to another exemplary embodiment. The integrated spring damper300 is similar in construction and function to the integrated springdamper 200.

As shown in FIG. 5, the integrated spring damper 300 includes a tubular(e.g., cylindrical, etc.) main body 302 (e.g., cylinder, housing, base,etc.). The ends of the main body 302 are closed by a cap 304 and abarrier 306 to define an internal volume. The integrated spring damper300 further includes a tubular (e.g., cylindrical, etc.) main tube 316.The main tube 316 is received in the internal volume of the main body302. The main tube 316 is configured to translate with respect to themain body 302. The distal end of the main tube 316 is closed by a cap318. The integrated spring damper 300 includes a first eyelet 320 and asecond eyelet 322 with which the integrated spring damper 300 is coupledto an axle assembly.

As shown in FIG. 6, a main piston 324 is disposed in the internal volumeof the main body 302 and separates the internal volume into a firstchamber 326 (e.g., compression chamber) and a second chamber 328 (e.g.,extension chamber). A dividing piston 330 (e.g., floating piston) isdisposed in the main tube 316 and separates the internal volume of themain tube 316 into first inner chamber 332 and a second inner chamber334. First inner chamber 332 is open to (i.e., in fluid communication)first chamber 326, according to an exemplary embodiment. A recoil damper336 including a recoil piston 338 is disposed within the internal volumeof the main body 302 between the main piston 324 and the barrier 306. Abypass manifold 340 is coupled to the side of the main body 302 andincludes a passage 342 through which hydraulic fluid may pass betweenthe first chamber 326 and the second chamber 328, and a flow controldevice 348 is disposed within the bypass manifold 340 along the passage342. The second inner chamber 334 may be in fluid communication withexternal devices, such as one or more reservoirs (e.g., centralreservoir, tank), an accumulator, or device allowing the pressure of thegas to be adjusted. The pressure of the gas may be adjusted by removingor adding a volume of gas to adjust the suspension ride height.

As shown in FIG. 7, the integrated spring damper 300 includes a sensor,shown as ride height sensor 360. The ride height sensor 360 includes afirst end 362 and a second end 364. According to an exemplaryembodiment, the ride height sensor 360 is coupled to the exterior of theintegrated spring damper 300, with the first end 362 coupled to the mainbody 302 and the second end 364 coupled to the cap 318. The ride heightsensor 360 is configured to have a relatively low profile such that itprotrudes a minimal distance from the main body 302. The low profile ofthe ride height sensor 360 reduces the risk of interference with othercomponents of the axle assembly. The ride height sensor 360 isconfigured to detect the displacement of the second end 364 relative tothe first end 362 and output a signal dependent on the displacement. Thedisplacement may be detected, for example, with a potentiometer (e.g., arotary potentiometer) that provides a variable output voltage to acontrol system. The output signal may be utilized by the control systemto determine the relative extension or compression of the integratedspring damper 300 and thereby the ride height of the vehicle withrespect to the ground. A control system may use the signal (e.g., asfeedback) to change the ride height of the vehicle by supplying a gas toor removing a gas from the second inner chamber 334 (e.g., through anaperture 354 from a gas reservoir).

Referring next to FIGS. 8A-8B, an integrated spring damper 400 is shown,according to another exemplary embodiment. The integrated spring damper400 is similar in construction and function to the integrated springdamper 100. The integrated spring damper 400 includes a tubular (e.g.,cylindrical, etc.) main body 402 (e.g., cylinder, housing, base, etc.).The ends of the main body 402 are closed by a cap 404 and a barrier 406to define an internal volume that is separated into a central chamberand an annular, outer chamber by an inner tube 410. The end of the innertube 410 proximate to the barrier 406 is closed with a cap 412. Theintegrated spring damper 400 further includes a tubular (e.g.,cylindrical, etc.) main tube 416. The main tube 416 is received in theinternal volume of the main body 402. The main tube 416 is configured totranslate with respect to the main body 402. The distal end of the maintube 416 is closed by a cap 418. The integrated spring damper 400includes a first eyelet 420 and a second eyelet 422 with which theintegrated spring damper 400 is coupled to an axle assembly.

A main piston 424 is disposed in an outer annular chamber definedbetween the main body 402 and the inner tube 410 and separates the outerannular chamber into first annular chamber 426 and a second annularchamber 428. A dividing piston 430 (e.g., floating piston) is disposedin the inner chamber defined by the inner tube 410 and separates theinner chamber into first inner chamber 432 and a second inner chamber434. According to an exemplary embodiment, the first inner chamber 432is in fluid communication with first annular chamber 426.

A bypass manifold 440 is coupled to the side of the main body 402 andincludes a passage 442 through which hydraulic fluid may pass betweenthe first annular chamber 426 and the second annular chamber 428. A flowcontrol device 448 is disposed within the bypass manifold 440 along thepassage 442. The second inner chamber 434 may be in fluid communicationwith external devices, such as one or more reservoirs (e.g., centralreservoir, tank), an accumulator, or device allowing the pressure of thegas to be adjusted. The pressure of the gas may be adjusted by removingor adding a volume of gas to adjust the suspension ride height.

The integrated spring damper 400 includes a sensor, shown as ride heightsensor 460. The ride height sensor 460 includes a first end 462 and asecond end 464. According to the exemplary embodiment shown in FIG. 8B,the ride height sensor 460 is positioned in the interior of theintegrated spring damper 400 with the first end 462 coupled to the cap404 and the second end 464 coupled to the cap 418. The ride heightsensor 460 extends through openings in the cap 412 and the dividingpiston 430. Positioning the ride height sensor 460 in the interior ofthe integrated spring damper 400 reduces the risk of interference withother components of the axle assembly. According to the exemplaryembodiment shown in FIGS. 8A-8B, the ride height sensor 460 is generallycentrally positioned (e.g., along a center line, coaxial, etc.) withinthe interior of the main tube 416. In other embodiments, the ride heightsensor 460 may be offset to one side of the integrated spring damper400.

Referring next to FIGS. 9A-9B, an integrated spring damper 500 is shown,according to another exemplary embodiment. The integrated spring damper500 is similar in construction and function to the integrated springdamper 200. The integrated spring damper 500 includes a tubular (e.g.,cylindrical, etc.) main body 502 (e.g., cylinder, housing, base, etc.).The ends of the main body 502 are closed by a cap 504 and a barrier 506to define an internal volume. A main piston 524 is disposed in theinternal volume of the main body 502 and separates the internal volumeinto a first chamber 526 and a second chamber 528. A bypass manifold 540includes a passage 542 through which hydraulic fluid may pass betweenthe first chamber 526 and the second chamber 528 and a flow controldevice 548 disposed within the cap 504 along the passage 542.

The passage 542 of the bypass manifold 540 opens into the second chamber528 through an aperture 546 in the main body 502 (e.g., the sidewall ofthe chambers 526 and 528). The passage 542 extends through the body ofthe cap 504 and opens into the first chamber 526 through an aperture 544provided in the cap 504 (e.g., the end wall of the first chamber 526).By providing the aperture 544 at the end of the first chamber 526 ratherthan along the sidewall of the first chamber 526, the stroke length ofthe integrated spring damper 500 is increased and the dead length (e.g.,the difference between the stroke length and the total length of theintegrated spring damper 500) is reduced.

Referring next to FIGS. 10A-10B, an integrated spring damper 600 isshown, according to another exemplary embodiment. The integrated springdamper 600 is similar in construction and function to the integratedspring damper 100. The integrated spring damper 600 includes a tubular(e.g., cylindrical, etc.) main body 602 (e.g., cylinder, housing, base,etc.). The ends of the main body 602 are closed by a cap 604 and abarrier 606 to define an internal volume that is separated into acentral chamber and an annular, outer chamber by an inner tube 610. Theend of the inner tube 610 proximate to the barrier 606 is closed with acap 612. The integrated spring damper 600 further includes a tubular(e.g., cylindrical, etc.) main tube 616. The main tube 616 is receivedin the internal volume of the main body 602. The main tube 616 isconfigured to translate with respect to the main body 602. The distalend of the main tube 616 is closed by a cap 618. The integrated springdamper 600 includes a first eyelet 620 and a second eyelet 622 withwhich the integrated spring damper 600 is coupled to an axle assembly.

A main piston 624 is disposed in an outer annular chamber definedbetween the main body 602 and the inner tube 610 and separates the outerannular chamber into first annular chamber 626 and a second annularchamber 628. A dividing piston 630 (e.g., floating piston) is disposedin the inner chamber defined by the inner tube 610 and separates theinner chamber into a first inner chamber 632 and a second inner chamber634. The first inner chamber 632 is in fluid communication with thefirst annular chamber 626 through one or more apertures 636 in the innertube 610, and second inner chamber 634 is in fluid communication with achamber between cap 612 and cap 618 via apertures in the cap 612.

A bypass manifold 640 includes a passage 642 through which hydraulicfluid may pass between the first inner chamber 632 and the secondannular chamber 628 and a flow control device 648 disposed within thecap 604 along the passage 642. The passage 642 of the bypass manifold640 opens into the first inner chamber 632 through an aperture 644 inthe cap 604 and into the second annular chamber 628 through an aperture646 in the main body 602. The passage 642 extends through the body ofthe cap 604 and opens into the first inner chamber 632 through anaperture 646 provided in the cap 604.

The integrated spring damper 600 additionally includes a sensor, shownas ride height sensor 660. The ride height sensor 660 includes a firstend 662 and a second end 664. According to an exemplary embodiment, theride height sensor 660 is positioned in the interior of the integratedspring damper 600 with the first end 662 passing through the flowcontrol device 648 and coupled to the cap 604 and the second end 664coupled to the cap 618. The ride height sensor 660 extends throughopenings in the cap 612 and the dividing piston 630.

Referring to FIGS. 11A-11B, an integrated spring damper 700 is shown,according to another exemplary embodiment. The integrated spring damper700 is similar in construction and function to the integrated springdamper 600. The integrated spring damper 700 includes a bypass manifold740. The bypass manifold 740 defines a passage 742 through whichhydraulic fluid may pass between a first inner chamber 732 and a secondannular chamber 728, and a flow control device 748 is disposed withinthe bypass manifold 740 along the passage 742. The passage 742 includesone or more end portions 745 formed in a cap 704 and an annular portion747 between a main body 702 and an outer wall and extending from the cap704 to a barrier 706. The passage 742 is in fluid communication with afirst inner chamber 732 through an aperture 744 in the cap 704 and witha second annular chamber 728 through one or more apertures 746 in themain body 702.

Referring to FIGS. 12A-12F, an integrated spring damper 800 is shown,according to another exemplary embodiment. As shown in FIG. 12A, theintegrated spring damper 800 includes a tubular (e.g., cylindrical,etc.) main body (e.g., cylinder, housing, base, etc.), shown as mainbody 802. In one embodiment, the main body 802 is manufactured using anextrusion process. In an alternative embodiment, the main body 802 ismanufactured using a casting process. As shown in FIGS. 12A and 12C, acap, shown as cap 804, and a barrier, shown as barrier 806, are disposedon opposing ends of the main body 802, defining an internal volume. Theintegrated spring damper 800 further includes a tubular (e.g.,cylindrical, etc.) element, shown as main tube 816. The main tube 816 isat least partially received within the internal volume of the main body802. The main tube 816 is configured to translate with respect to themain body 802. As shown in FIG. 12C, a cap, shown as cap 818, isdisposed at a distal end of the main tube 816. The cap 804, barrier 806,and cap 818 may be coupled to the respective components with a threadedconnection or with another coupling mechanism (e.g., welding, a frictionweld, brazing, interference fit, etc.). As shown in FIG. 12A, in someembodiments, the integrated spring damper 800 includes a lockingmechanism, shown as locking mechanism 870. In one embodiment, thelocking mechanism 870 is configured to position (e.g., lock, index,etc.) the cap 804 in a target orientation relative to the main body 802.In one embodiment, the locking mechanism 870 includes a set screw thatis tightened to facilitate locking the cap 804 in the targetorientation. The locking mechanism 870 may facilitate indexing a lowermount of the integrated spring damper 800 relative to other componentsthereof and thereby facilitate mounting integrated spring damper 800onto a vehicle.

According to an exemplary embodiment, the integrated spring damper 800includes a first mounting portion (e.g., a lower mounting portion,etc.), shown as eyelet 820, with which the integrated spring damper 800is coupled to one portion of an axle assembly (e.g., a lower portion ofthe axle assembly, etc.). According to an exemplary embodiment, theintegrated spring damper 800 is coupled on one end (e.g., via the eyelet820 on a lower end, etc.) to a moveable member of the axle assembly(e.g., a lower support arm, etc.). According to an exemplary embodiment,the eyelet 820 is integrally formed with the cap 804. As shown in FIG.12A, the integrated spring damper 800 includes a second mounting portion(e.g., an upper mounting portion, a pin mount, etc.), shown as uppermount 807. The upper mount 807 is configured to couple an opposingsecond end (e.g., an upper end, etc.) of the integrated spring damper800 to a vehicle body, frame member, or part thereof (e.g., chassis,side plate, hull, etc.), shown as side plate 1000.

As shown in FIGS. 12A and 12C-12D, the upper mount 807 includes a firstmounting member 808, a second mounting member 810, a third mountingmember 812, and a fourth mounting member 814. As shown in FIGS. 12A and12D, the first mounting member 808 is positioned such that a top surfaceof the first mounting member 808 abuts a first surface of the side plate1000, shown as bottom surface 1002. In one embodiment, the firstmounting member 808 is constructed from a metal or wear resistantmaterial. As shown in FIG. 12C-12D, the second mounting member 810includes a portion (e.g., a lower portion, a first portion, anon-protruded portion, etc.) that is positioned between the cap 818 andthe first mounting member 808. In one embodiment, the second mountingmember 810 is a resilient member, such as a flexible urethane, thatserves as an isolator and an elastomeric spacer. The second mountingmember 810 may be configured to isolate the cap 818 from at least one ofthe first mounting member 808 and the side plate 1000. In someembodiments, the first mounting member 808 and the second mountingmember 810 are annular and circular in shape. In other embodiments, thefirst mounting member 808 and the second mounting member 810 haveanother shape (e.g., discus square, hexagonal, etc.).

As shown in FIGS. 12A and 12D, the fourth mounting member 814 ispositioned between the side plate 1000 and the third mounting member812. A second surface, shown as top surface 1004, of the side plate 1000is in contact with a bottom surface of the fourth mounting member 814,and the third mounting member 812 is disposed on a top surface of thefourth mounting member 814. The first mounting member 808 and the fourthmounting member 814 are spaced to receive the side plate 1000. In oneembodiment, the fourth mounting member 814 is a resilient member, suchas a flexible urethane, that serves as an isolator and an elastomericspacer. The fourth mounting member 814 may be configured to isolate thethird mounting member 812 from the side plate 1000. In one embodiment,the third mounting member 812 is constructed from a metal or wearresistant material. In some embodiments, the third mounting member 812and the fourth mounting member 814 are annular and circular in shape. Inother embodiments, the third mounting member 812 and the fourth mountingmember 814 have another shape (e.g., discus square, hexagonal, etc.).

As shown in FIG. 12D, the first mounting member 808 defines an aperture,shown as aperture 809, that corresponds with (e.g., aligns with,cooperates with, etc.) an aperture defined by side plate 1000, shown asside plate aperture 1006. The second mounting member 810 includes aprotruded portion (e.g., a second portion, an upper portion, etc.) thatextends through the aperture 809 and the side plate aperture 1006 andengages with a recess, shown as recess 815, defined by the fourthmounting member 814. In one embodiment, the recess 815 receives theprotruded portion of the second mounting member 810. The second mountingmember 810 defines an aperture, shown as bore 811, that extendslongitudinally through the second mounting member 810 and aligns with(e.g., cooperates with, etc.) an aperture, shown as aperture 813, and anaperture, shown as aperture 817, defined by the third mounting member812 and the fourth mounting member 814, respectively. The bore 811,aperture 813, and aperture 817 receive a protruded portion 819 of thecap 818.

As shown in FIG. 12C, a main piston, shown as main piston 824, isdisposed in the internal volume of the main body 802. The main piston824 is coupled to the main tube 816 and slidably engages the main body802. The main piston 824 separates the internal volume into a firstchamber 826 (e.g., compression chamber, etc.) and a second chamber 828(e.g., extension chamber, etc.). The first chamber 826 is a generallycylindrical chamber that includes the portion of the internal volume ofthe main body 802 between the main piston 824 and the cap 804. Thesecond chamber 828 is an annular chamber defined between the main body802 and the main tube 816 and extends between the main piston 824 andthe barrier 806. When the main tube 816 translates relative to the mainbody 802, the main piston 824 changes the volume of the first chamber826 and the second chamber 828. A dividing piston, shown as dividingpiston 830 (e.g., floating piston, etc.), is disposed in the main tube816 and slidably engages the main tube 816. The dividing piston 830separates the internal volume of the main tube 816 into a first innerchamber 832 and a second inner chamber 834. According to an exemplaryembodiment, the first inner chamber 832 is open to (i.e., in fluidcommunication with, etc.) the first chamber 826.

According to an exemplary embodiment, the first chamber 826, the secondchamber 828, and the first inner chamber 832 contain a generallynon-compressible fluid (e.g., hydraulic fluid, oil, etc.). According toan exemplary embodiment, the second inner chamber 834 contains agenerally compressible fluid that may include (e.g., at least 90%, atleast 95%) an inert gas such as nitrogen, argon, or helium, amongothers. In some embodiments, the second inner chamber 834 is in fluidcommunication with external devices, such as one or more reservoirs(e.g., central reservoir, tank, etc.), an accumulator, or a deviceallowing the pressure of the gas to be adjusted via a pressureregulation line. The pressure of the gas may be adjusted by removing oradding a volume of gas to adjust the suspension ride height.

According to an exemplary embodiment, the integrated spring damper 800includes a pressure regulation line that is located at a top portion(e.g., a top end, an upper end, etc.) of the integrated spring damper800. As shown in FIGS. 12A-12D, the integrated spring damper 800includes a port, shown as pressure regulation port 880, coupled to theprotruded portion 819 of the cap 818 (e.g., via a threaded interface,welded, etc.). As shown in FIGS. 12C-12D, the pressure regulation port880 defines a passageway, shown as inlet passageway 882. The protrudedportion 819 of the cap 818 defines a passageway, shown as intermediatepassageway 822. The intermediate passageway 822 cooperates with theinlet passageway 882 to define the pressure regulation line of theintegrated spring damper 800. The pressure regulation line extends fromthe pressure regulation port 880, through the protruded portion 819 ofthe cap 818, and into the second inner chamber 834 of the main tube 816.According to an exemplary embodiment, the pressure regulation line ofthe integrated spring damper 800 facilitates increasing or decreasing avolume of fluid (e.g., an inert gas, etc.) within the second innerchamber 834 of the main tube 816.

According to an exemplary embodiment, the pressure regulation port 880is positioned at the top of the integrated spring damper 800 to providea fixed or static location to fill or release gas from the second innerchamber 834 of the integrated spring damper 800. The pressure regulationport 880 is positioned to increase (e.g., maximize, etc.) the travel ofthe main tube 816 within the main body 802, thereby increasing thestroke of the integrated spring damper 800. By way of example, impulseforces transmitted to occupants within a vehicle from bumps, pot holes,etc. may be reduced by increasing the maximum stroke of the integratedspring damper 800. According to an exemplary embodiment, the pressureregulation port 880 is positioned above the side plate 1000 to reducethe risk of debris (e.g., dirt, rocks, mud, etc.) damaging or blockingthe pressure regulation port 880.

When the integrated spring damper 800 is compressed or extended, themain tube 816 translates relative to the main body 802. The gas held inthe second inner chamber 834 compresses or expands in response torelative movement between the main tube 816 and the dividing piston 830,which may remain relatively stationary but transmit pressure variationsbetween the incompressible hydraulic fluid in the first inner chamber832 and the compressible fluid in second inner chamber 834. The gas inthe second inner chamber 834 resists compression, providing a force thatis a function of the compressibility of the gas, the area of the piston,the volume and geometry of the second inner chamber 834, and the currentstate (e.g., initial pressure, etc.) of the gas, among other factors.The receipt of potential energy as the gas is compressed, storage ofpotential energy, and release of potential energy as the gas expandsprovide a spring function for the integrated spring damper 800.

In one embodiment, the dividing piston 830 defines a cup 831. Accordingto the exemplary embodiment shown in FIG. 12C, the dividing piston 830is positioned such that the cup 831 facilitates an increase in thevolume of the second inner chamber 834. In other embodiments, thedividing piston 830 is positioned such that the cup 831 facilitates anincrease in the volume of the first inner chamber 832. The dividingpiston 830 may be flipped and repositioned to selectively increase thevolume of the first inner chamber 832 or the second inner chamber 834 totune the performance of the integrated spring damper 800. As shown inFIG. 12C, the cap 818 defines a pocket, shown as cap pocket 823. The cappocket 823 is structured to increase the volume of the second innerchamber 834. In some embodiments, the cap pocket 823 and the cup 831increase the volume of the second inner chamber 834. In otherembodiments, at least one of the cap pocket 823 and the cup 831 are notdefined by the cap 818 and the dividing piston 830, respectively. By wayof example, increasing the volume of the second inner chamber 834 (i.e.,decreasing the gas pressure within the second inner chamber 834, etc.)may facilitate a softer ride (e.g., a smaller spring force, etc.), whiledecreasing the volume of the second inner chamber 834 (i.e., increasingthe gas pressure within the second inner chamber 834, etc.) mayfacilitate a stiffer ride (e.g., a greater spring force, etc.).

Referring again to FIG. 12C, a limiter, shown as recoil damper 836, isdisposed within the internal volume of the main body 802, between themain piston 824 and the barrier 806. The recoil damper 836 reduces therisk of damage to the main piston 824, barrier 806, the sidewall of mainbody 802, and still other components of integrated spring damper 800 byreducing the forces imparted by the main piston 824 as it travels towardan end of stroke (i.e., the maximum travel of the stroke, etc.).According to an exemplary embodiment, the recoil damper 836 includes arecoil piston, shown as recoil piston 838, positioned within the secondchamber 828 and a resilient member, shown as resilient member 839. Theresilient member 839 may include an interlaced wave spring (i.e., a flatwire compression spring, etc.), a coil spring, or another type ofspring. The resilient member 839 may be disposed between the recoilpiston 838 and the barrier 806. According to an exemplary embodiment,the resilient member 839 is not intended to substantially resist themovement of the main piston 824 but positions the recoil piston 838within the main body 802, such as after it has been displaced by themain piston 824. In other embodiments, the recoil damper 836 does notinclude a resilient member, and the recoil piston 838 may berepositioned using gravity or an alternative device.

Occupants within a vehicle experience large impulse forces as the mainpiston 824 contacts the barrier 806 or a component of the suspensionsystem engages a hard stop. The recoil damper 836 reduces such impulseforces transmitted to occupants within the vehicle by dissipating aportion of the kinetic energy of the main piston 824 and the main tube816 (i.e. provide a supplemental damping force, etc.) as the integratedspring damper 800 reaches an end of stroke (e.g., as the piston reachesa recoil end of stroke, as the piston reaches a jounce end of stroke,etc.).

Referring now to FIGS. 12E-12F, fluid may flow between the first chamber826 and the second chamber 828 through at least one of a first passage852 (e.g., conduit, bore, etc.) of a flow path, shown as first flow path850, and a second passage 862 of a flow path, shown as second flow path860, defined by a manifold, shown as bypass manifold 840. In otherembodiments, the bypass manifold 840 defines a different number ofpassages (e.g., one, three, etc.). According to an exemplary embodiment,the bypass manifold 840 is coupled to the side of the main body 802(e.g., removably coupled to the main body 802 with a plurality offasteners, etc.). In other embodiments, the bypass manifold 840 and themain body 802 are integrally formed (e.g., a unitary structure, etc.).According to an alternative embodiment, at least one of the firstpassage 852 and the second passage 862 are formed with tubular memberscoupled to an outer portion of the main body 802 or with flow passagesdefined by the main body 802.

According to the exemplary embodiment shown in FIGS. 12C and 12E-12F,damping forces are generated as the flow of fluid through the firstpassage 852 and the second passage 862 interacts with flow controlelements, shown as first flow control device 858 and second flow controldevice 868. According to an exemplary embodiment, the first flow controldevice 858 and the second flow control device 868 are bidirectional flowvalves disposed within the bypass manifold 840 along the first passage852 and the second passage 862, respectively. The first flow controldevice 858 and the second flow control device 868 may include washersthat differentially restrict a fluid flow based on the direction thatthe fluid is flowing. In other embodiments, the first flow controldevice 858 and the second flow control device 868 are other types offlow control device, such as pop off valves or orifices (e.g., variableflow orifices, etc.). In other embodiments, the first flow controldevice 858 and the second flow control device 868 are remotelypositioned but in fluid communication with the first chamber 826 and thesecond chamber 828.

According to an exemplary embodiment, the main body 802 defines aplurality of sets of openings. As shown in FIG. 12E, the plurality ofsets of openings include a first set having openings 854 and openings856. The openings 854 and the openings 856 are fluidly coupled by thefirst passage 852. As shown in FIG. 12F, the plurality of sets ofopenings include a second set having openings 864 and openings 866. Theopenings 864 and the openings 866 are fluidly coupled by the secondpassage 862. According to an exemplary embodiment, the first passage 852and the second passage 862 are offset relative to one another bothcircumferentially and longitudinally along the length of the main body802 and the bypass manifold 840. In other embodiments, the main body 802defines a different number of sets of openings (e.g., one, three, four,etc.), each set corresponding with one of the passages defined by thebypass manifold 840.

According to an exemplary embodiment, the integrated spring damper 800provides different damping forces in extension and retraction and alsodamping forces that vary based on the position of the main piston 824relative to the main body 802 (e.g., position dependent dampening,etc.). According to an exemplary embodiment, the integrated springdamper 800 provides recoil damping forces in jounce and compressiondamping forces in recoil as part of a spring force compensationstrategy. By way of example, the position dependent dampening of theintegrated spring damper 800 may function as follows. As the main piston824 translates within main body 802 (e.g., due to relative movementbetween components of a vehicle suspension system, etc.), variousopenings and their corresponding passages are activated and deactivated.According to an exemplary embodiment, fluid flows through the activatedopenings and their corresponding passages to provide damping forces thatvary based on position and direction of travel of the main piston 824within the main body 802.

Movement of the main tube 816 relative to the main body 802 translatesthe main piston 824, causing the volume of the first chamber 826 and thesecond chamber 828 to vary. When the integrated spring damper 800compresses, the volume of the first chamber 826 decreases while thevolume of the second chamber 828 increases. The fluid is forced from thefirst chamber 826 through at least one of the openings 854 of the firstpassage 852 and the openings 864 of the second passage 862 (e.g., basedon the position of the main piston 824 within the main body 802, etc.).The fluid flows through at least one the first passage 852 and thesecond passage 862 past the first flow control device 858 and the secondflow control device 868 and out of the openings 856 and the openings 866into the second chamber 828. The resistance to the flow of the fluidalong at least one of the first passage 852 and the second passage 862and the interaction thereof with the first flow control device 858 andthe second flow control device 868 provides a damping function for theintegrated spring damper 800 that is independent of the spring function.By way of example, if the non-compressible fluid is able to flow throughboth the first passage 852 and the second passage 862, the dampeningprovided by the integrated spring damper 800 will be less than if fluidis able to flow through only one of the first passage 852 and the secondpassage 862. Therefore, as the main piston 824 moves towards the cap804, the integrated spring damper 800 provides a first dampeningcharacteristic (e.g., less dampening, etc.) when the openings 854 andthe openings 864 are active and a second dampening characteristics(e.g., more dampening, etc.) when only the openings 864 are active(e.g., because the main piston 824 deactivates the openings 854, whichmay include the openings 854 being positioned within the second chamber828, etc.).

Referring to FIGS. 13A-13F, an integrated spring damper 900 is shown,according to another exemplary embodiment. The integrated spring damper900 is similar in construction and function to the integrated springdamper 800.

As shown in FIG. 13A, the integrated spring damper 900 includes atubular (e.g., cylindrical, etc.) main body (e.g., cylinder, housing,base, etc.), shown a main body 902. In one embodiment, the main body 902is manufactured using an extrusion process. In an alternativeembodiment, the main body 902 is manufactured using a casting process.As shown in FIGS. 13A and 13C, a cap, shown as cap 904, and a barrier,shown as barrier 906, are disposed on opposing ends of the main body902, defining an internal volume. According to an exemplary embodiment,the integrated spring damper 900 includes a wearband, shown as wearband990, positioned between interfacing surfaces of the main body 902 andthe main piston 924. The wearband 990 increases the side load andbending load capabilities of the integrated spring damper 900. Theintegrated spring damper 900 further includes a tubular (e.g.,cylindrical, etc.) element, shown as main tube 916. The main tube 916 isat least partially received within the internal volume of the main body902. The main tube 916 is configured to translate with respect to themain body 902. As shown in FIGS. 13A-13C, a cap, shown as cap 918, isdisposed at a distal end of the main tube 916. The cap 904, barrier 906,and cap 918 may be coupled to the respective components with a threadedconnection, a friction weld, or with another coupling mechanism (e.g.,welding, brazing, interference fit, etc.). In some embodiments, theintegrated spring damper 900 includes a plurality of O-rings positionedbetween components that are coupled with a threaded connection to reducethe risk of contaminants entering into the integrated spring damper 900.

According to the exemplary embodiment shown in FIG. 13A, the integratedspring damper 900 includes a locking mechanism, shown as lockingmechanism 970. In one embodiment, the locking mechanism 970 isconfigured to position (e.g., lock, index, etc.) the cap 904 in a targetorientation relative to the main body 902. As shown in FIG. 13A, thelocking mechanism 970 includes a retainer, shown as retainer 972. Theretainer 972 is removably coupled to the main body 902 with fasteners974. The retainer 972 engages a face, shown as face 976, defined by(e.g., machined into, etc.) the main body 902. The cap 904 includes aninterfacing surface, shown as flat 978. The retainer 972 may be coupledto the main body 902 via the fasteners 974 when the flat 978 aligns withthe face 976 (i.e., indicating the target orientation, etc.) tofacilitate locking the cap 904 in the target orientation. The lockingmechanism 970 may facilitate indexing a lower mount of the integratedspring damper 900 relative to other components thereof and therebyfacilitate mounting integrated spring damper 900 onto a vehicle.

According to an exemplary embodiment, the integrated spring damper 900includes a first mounting portion (e.g., a lower mounting portion,etc.), shown as eyelet 920, with which the integrated spring damper 900is coupled to one portion of an axle assembly (e.g., a lower portion ofthe axle assembly, etc.). According to an exemplary embodiment, theintegrated spring damper 900 is coupled on one end (e.g., via the eyelet920 on a lower end, etc.) to a moveable member of the axle assembly(e.g., a lower support arm, etc.). According to an exemplary embodiment,the eyelet 920 is integrally formed with the cap 904. According to anexemplary embodiment, the eyelet 920 receives a pin to rotatably couplethe eyelet 920 to a lower portion of the axle assembly (e.g., lowersupport arm, etc.). In one embodiment, the pin is sized to allow anelastomeric bushing to fit between the pin and the lower support arm. Asshown in FIG. 13A, the integrated spring damper 900 includes a secondmounting portion (e.g., an upper mounting portion, a pin mount, etc.),shown as upper mount 907. The upper mount 907 is configured to couple anopposing second end (e.g., an upper end, etc.) of the integrated springdamper 900 to a vehicle body, frame member, or part thereof (e.g.,chassis, side plate, hull, etc.), shown as side plate 1000.

As shown in FIGS. 13A and 13C-13D, the upper mount 907 includes a firstmounting member 908, a second mounting member 910, a third mountingmember 912, and a fourth mounting member 914. As shown in FIGS. 13A and13D, the first mounting member 908 is positioned such that a top surfaceof the first mounting member 908 abuts a first surface of the side plate1000, shown as bottom surface 1002. In one embodiment, the firstmounting member 908 is constructed from a metal or wear resistantmaterial. As shown in FIG. 13C-13D, the second mounting member 910includes a portion (e.g., a lower portion, a first portion, anon-protruded portion, etc.) that is positioned between the cap 918 andthe first mounting member 908. In one embodiment, the second mountingmember 910 is a resilient member, such as a flexible urethane, thatserves as an isolator and an elastomeric spacer. The second mountingmember 910 may be configured to isolate the cap 918 from at least one ofthe first mounting member 908 and the side plate 1000. In someembodiments, the first mounting member 908 and the second mountingmember 910 are annular and circular in shape. In other embodiments, thefirst mounting member 908 and the second mounting member 910 haveanother shape (e.g., discus square, hexagonal, etc.).

As shown in FIGS. 13A and 13D, the fourth mounting member 914 ispositioned between the side plate 1000 and the third mounting member912. A second surface, shown as top surface 1004, of the side plate 1000is in contact with a bottom surface of the fourth mounting member 914,and the third mounting member 912 is disposed on a top surface of thefourth mounting member 914. The first mounting member 908 and the fourthmounting member 914 are spaced to receive the side plate 1000. In oneembodiment, the fourth mounting member 914 is a resilient member, suchas a flexible urethane, that serves as an isolator and an elastomericspacer. The fourth mounting member 914 may be configured to isolate thethird mounting member 912 from the side plate 1000. In one embodiment,the third mounting member 912 is constructed from a metal or wearresistant material. In some embodiments, the third mounting member 912and the fourth mounting member 914 are annular and circular in shape. Inother embodiments, the third mounting member 912 and the fourth mountingmember 914 have another shape (e.g., discus square, hexagonal, etc.).

As shown in FIG. 13D, the first mounting member 908 defines an aperture,shown as aperture 909, that corresponds with (e.g., aligns with,cooperates with, etc.) an aperture defined by side plate 1000, shown asside plate aperture 1006. The second mounting member 910 includes aprotruded portion (e.g., a second portion, an upper portion, etc.) thatextends through the aperture 909 and the side plate aperture 1006 andengages with an aperture, shown as aperture 915, defined by the fourthmounting member 914. In one embodiment, the aperture 915 receives theprotruded portion of the second mounting member 910. The second mountingmember 910 defines an aperture, shown as bore 911, that extendslongitudinally through the second mounting member 910 and aligns with(e.g., cooperates with, etc.) an aperture, shown as aperture 913,defined by the third mounting member 912. The bore 911 and the aperture913 receive a protruded portion 919 of the cap 918. In one embodiment,the protruded portion 919 is coupled to the cap 918 by a friction weld921. In other embodiments, the cap 918 and the protruded portion 919 areintegrally formed. According to an exemplary embodiment, the frictionweld 921 between the cap 918 and the protruded portion 919 is positionedto reduce stress concentration within the cap 918 and the integratedspring damper 900 such that the side plate 1000 carries substantiallyall of the stresses generated during the use of the integrated springdamper 900. In some embodiments, the cap 918 includes notches, shown asnotches 923. The notches 923 may be at least one of shaped andpositioned to substantially reduce stress concentration within the cap918.

As shown in FIG. 13C, a main piston, shown as main piston 924, isdisposed in the internal volume of the main body 902. The main piston924 is coupled to the main tube 916 and slidably engages the main body902. The main piston 924 separates the internal volume into a firstchamber 926 (e.g., compression chamber, etc.) and a second chamber 928(e.g., extension chamber, etc.). The first chamber 926 is a generallycylindrical chamber that includes the portion of the internal volume ofthe main body 902 between the main piston 924 and the cap 904. Thesecond chamber 928 is an annular chamber defined between the main body902 and the main tube 916 and extends between the main piston 924 andthe barrier 906. When the main tube 916 translates relative to the mainbody 902, the main piston 924 changes the volume of the first chamber926 and the second chamber 928. A dividing piston, shown as dividingpiston 930 (e.g., floating piston, etc.), is disposed in the main tube916 and slidably engages the main tube 916. The dividing piston 930separates the internal volume of the main tube 916 into a first innerchamber 932 and a second inner chamber 934. According to an exemplaryembodiment, the first inner chamber 932 is open to (i.e., in fluidcommunication with, etc.) the first chamber 926.

According to an exemplary embodiment, the first chamber 926, the secondchamber 928, and the first inner chamber 932 contain a generallynon-compressible fluid (e.g., hydraulic fluid, oil, etc.). According toan exemplary embodiment, the second inner chamber 934 contains agenerally compressible fluid that may include (e.g., at least 90%, atleast 95%) an inert gas such as nitrogen, argon, or helium, amongothers. In some embodiments, the second inner chamber 934 is in fluidcommunication with external devices, such as one or more reservoirs(e.g., central reservoir, tank, etc.), an accumulator, or a deviceallowing the pressure of the gas to be adjusted via a pressureregulation line. The pressure of the gas may be adjusted by removing oradding a volume of gas to adjust the suspension ride height.

According to an exemplary embodiment, the integrated spring damper 900includes a pressure regulation line that is located at a top portion(e.g., a top end, an upper end, etc.) of the integrated spring damper900. As shown in FIGS. 13A-13D, the integrated spring damper 900includes a port, shown as pressure regulation port 980, coupled to theprotruded portion 919 of the cap 918 (e.g., via a threaded interface,welded, etc.). As shown in FIGS. 13C-13D, the pressure regulation port980 defines a passageway, shown as inlet passageway 982. The protrudedportion 919 of the cap 918 defines a passageway, shown as intermediatepassageway 922. The intermediate passageway 922 cooperates with theinlet passageway 982 to define the pressure regulation line of theintegrated spring damper 900. The pressure regulation line extends fromthe pressure regulation port 980, through the protruded portion 919 ofthe cap 918, and into the second inner chamber 934 of the main tube 916.According to an exemplary embodiment, the pressure regulation line ofthe integrated spring damper 900 facilitates increasing or decreasing avolume of fluid (e.g., an inert gas, etc.) within the second innerchamber 934 of the main tube 916.

According to an exemplary embodiment, the pressure regulation port 980is positioned at the top of the integrated spring damper 900 to providea fixed or static location to fill or release gas from the second innerchamber 934 of the integrated spring damper 900. The pressure regulationport 980 is positioned to increase (e.g., maximize, etc.) the travel ofthe main tube 916 within the main body 902, thereby increasing thestroke of the integrated spring damper 900. By way of example, impulseforces transmitted to occupants within a vehicle from bumps, pot holes,etc. may be reduced by increasing the maximum stroke of the integratedspring damper 900. According to an exemplary embodiment, the pressureregulation port 980 is positioned above the side plate 1000 to reducethe risk of debris (e.g., dirt, rocks, mud, etc.) damaging or blockingthe pressure regulation port 980.

When the integrated spring damper 900 is compressed or extended, themain tube 916 translates relative to the main body 902. The gas held inthe second inner chamber 934 compresses or expands in response torelative movement between the main tube 916 and the dividing piston 930,which may remain relatively stationary but transmit pressure variationsbetween the incompressible hydraulic fluid in the first inner chamber932 and the compressible fluid in second inner chamber 934. The gas inthe second inner chamber 934 resists compression, providing a force thatis a function of the compressibility of the gas, the area of the piston,the volume and geometry of the second inner chamber 934, and the currentstate (e.g., initial pressure, etc.) of the gas, among other factors.The receipt of potential energy as the gas is compressed, storage ofpotential energy, and release of potential energy as the gas expandsprovide a spring function for the integrated spring damper 900.

In one embodiment, the dividing piston 930 defines a cup 931. Accordingto the exemplary embodiment shown in FIG. 13C, the dividing piston 930is positioned such that the cup 931 facilitates an increase in thevolume of the first inner chamber 932. In alternate embodiments, thedividing piston 930 is positioned such that the cup 931 facilitates anincrease in the volume of the second inner chamber 934. The dividingpiston 930 may be flipped and repositioned to selectively increase thevolume of the first inner chamber 932 or the second inner chamber 934 totune the performance of the integrated spring damper 900. In otherembodiments, the cup 931 is not defined by the dividing piston 930. Byway of example, increasing the volume of the second inner chamber 934(i.e., decreasing the gas pressure within the second inner chamber 934,etc.) may facilitate a softer ride (e.g., a smaller spring force, etc.),while decreasing the volume of the second inner chamber 934 (i.e.,increasing the gas pressure within the second inner chamber 934, etc.)may facilitate a stiffer ride (e.g., a greater spring force, etc.).

Referring again to FIG. 13C, a limiter, shown as recoil damper 936, isdisposed within the internal volume of the main body 902, between themain piston 924 and the barrier 906. The recoil damper 936 reduces therisk of damage to the main piston 924, barrier 906, the sidewall of mainbody 902, and still other components of integrated spring damper 900 byreducing the forces imparted by the main piston 924 as it travels towardan end of stroke (i.e., the maximum travel of the stroke, etc.).According to an exemplary embodiment, the recoil damper 936 includes arecoil piston, shown as recoil piston 938, positioned within the secondchamber 928 and a resilient member, shown as resilient member 939. Theresilient member 939 may include an interlaced wave spring (i.e., a flatwire compression spring, etc.), a coil spring, or another type ofspring. The resilient member 939 may be disposed between the recoilpiston 938 and the barrier 906. According to an exemplary embodiment,the resilient member 939 is not intended to substantially resist themovement of the main piston 924 but positions the recoil piston 938within the main body 902, such as after it has been displaced by themain piston 924. In other embodiments, the recoil damper 936 does notinclude a resilient member, and the recoil piston 938 is repositionedusing gravity or an alternative device.

Occupants within a vehicle experience large impulse forces as the mainpiston 924 contacts the barrier 906 or a component of the suspensionsystem engages a hard stop. The recoil damper 936 reduces such impulseforces transmitted to occupants within the vehicle by dissipating aportion of the kinetic energy of the main piston 924 and the main tube916 (i.e. provide a supplemental damping force, etc.) as the integratedspring damper 900 reaches an end of stroke (e.g., as the piston reachesa recoil end of stroke, as the piston reaches a jounce end of stroke,etc.). Recoil dampers (e.g., recoil damper 836, recoil damper 936, etc.)are discussed in U.S. patent application Ser. No. 13/792,151, filed Mar.10, 2013, which is incorporated herein by reference in its entirety.

Referring now to FIGS. 13E-13F, fluid may flow between the first chamber926 and the second chamber 928 through at least one of a first passage952 (e.g., conduit, bore, etc.) of a flow path, shown as first flow path950, and a second passage 962 of a flow path, shown as second flow path960, defined by a manifold, shown as bypass manifold 940. In otherembodiments, the bypass manifold 940 defines a different number ofpassages (e.g., one, three, etc.). According to an exemplary embodiment,the bypass manifold 940 is coupled to the side of the main body 902(e.g., removably coupled to the main body 902 with a plurality offasteners, etc.). In other embodiments, the bypass manifold 940 and themain body 902 are integrally formed (e.g., a unitary structure, etc.).According to an alternative embodiment, at least one of the firstpassage 952 and the second passage 962 are formed with tubular memberscoupled to an outer portion of the main body 902 or with flow passagesdefined by the main body 902.

According to the exemplary embodiment shown in FIGS. 13C and 13E-13F,damping forces are generated as the flow of fluid through the firstpassage 952 and the second passage 962 interacts with flow controlelements, shown as first flow control device 958 and second flow controldevice 968. According to an exemplary embodiment, the first flow controldevice 958 and the second flow control device 968 are bidirectional flowvalves disposed within the bypass manifold 940 along the first passage952 and the second passage 962, respectively. The first flow controldevice 958 and the second flow control device 968 may include washersthat differentially restrict a fluid flow based on the direction thatthe fluid is flowing. In other embodiments, the first flow controldevice 958 and the second flow control device 968 are other types offlow control devices, such as pop off valves or orifices (e.g., variableflow orifices, etc.). In other embodiments, the first flow controldevice 958 and the second flow control device 968 are remotelypositioned but in fluid communication with the first chamber 926 and thesecond chamber 928.

According to an exemplary embodiment, the main body 902 defines aplurality of sets of openings. As shown in FIG. 13E, the plurality ofsets of openings include a first set having openings 954 and openings956. The openings 954 and the openings 956 are fluidly coupled by thefirst passage 952. As shown in FIG. 13F, the plurality of sets ofopenings include a second set having openings 964 and openings 966. Theopenings 964 and the openings 966 are fluidly coupled by the secondpassage 962. According to an exemplary embodiment, the first passage 952and the second passage 962 are offset relative to one another bothcircumferentially and longitudinally along the length of the main body902 and the bypass manifold 940. In other embodiments, the main body 902defines a different number of sets of openings (e.g., one, three, four,etc.), each set corresponding with one of the passages defined by thebypass manifold 940.

According to an exemplary embodiment, the integrated spring damper 900provides different damping forces in extension and retraction and alsodamping forces that vary based on the position of the main piston 924relative to the main body 902 (e.g., position dependent dampening,etc.). Position dependent dampening is discussed in U.S. Pat. No.8,801,017, issued Aug. 12, 2014, which is incorporated herein byreference in its entirety. According to an exemplary embodiment, theintegrated spring damper 900 provides recoil damping forces in jounceand compression damping forces in recoil as part of a spring forcecompensation strategy. By way of example, the position dependentdampening of the integrated spring damper 900 may function as follows.As the main piston 924 translates within main body 902 (e.g., due torelative movement between components of a vehicle suspension system,etc.), various openings and their corresponding passages are activatedand deactivated. According to an exemplary embodiment, fluid flowsthrough the activated openings and their corresponding passages toprovide damping forces that vary based on position and direction oftravel of the main piston 924 within the main body 902.

Movement of the main tube 916 relative to the main body 902 translatesthe main piston 924, causing the volume of the first chamber 926 and thesecond chamber 928 to vary. When the integrated spring damper 900compresses, the volume of the first chamber 926 decreases while thevolume of the second chamber 928 increases. The fluid is forced from thefirst chamber 926 through at least one of the openings 954 of the firstpassage 952 and the openings 964 of the second passage 962 (e.g., basedon the position of the main piston 924 within the main body 902, etc.).The fluid flows through at least one the first passage 952 and thesecond passage 962 past the first flow control device 958 and the secondflow control device 968 and out of the openings 956 and the openings 966into the second chamber 928. The resistance to the flow of the fluidalong at least one of the first passage 952 and the second passage 962and the interaction thereof with the first flow control device 958 andthe second flow control device 968 provides a damping function for theintegrated spring damper 900 that is independent of the spring function.By way of example, if the non-compressible fluid is able to flow throughboth the first passage 952 and the second passage 962, the dampeningprovided by the integrated spring damper 900 will be less than if fluidis able to flow through only one of the first passage 952 and the secondpassage 962. Therefore, as the main piston 924 moves towards the cap904, the integrated spring damper 900 provides a first dampeningcharacteristic (e.g., less dampening, etc.) when the openings 954 andthe openings 964 are active and a second dampening characteristics(e.g., more dampening, etc.) when only the openings 964 are active(e.g., because the main piston 924 deactivates the openings 954, whichmay include the openings 954 being positioned within the second chamber928, etc.).

It should be understood that the components of various suspensionelements described herein may have various cross-sectional shapes (e.g.,cylindrical, rectangular, square, hexagonal, etc.). According to anexemplary embodiment, the components of the integrated spring dampersare coupled with seals (e.g., bushings, wear bands, o-rings, etc.) thatare configured to prevent pressurized fluid from passing between thechambers discussed herein or leaking out of the integrated springdampers.

The construction and arrangements of the integrated spring damper, asshown in the various exemplary embodiments, are illustrative only.Although only a few embodiments have been described in detail in thisdisclosure, many modifications are possible (e.g., variations in sizes,dimensions, structures, shapes and proportions of the various elements,values of parameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter described herein. Someelements shown as integrally formed may be constructed of multiple partsor elements, the position of elements may be reversed or otherwisevaried, and the nature or number of discrete elements or positions maybe altered or varied. The order or sequence of any process, logicalalgorithm, or method steps may be varied or re-sequenced according toalternative embodiments. Other substitutions, modifications, changes andomissions may also be made in the design, operating conditions andarrangement of the various exemplary embodiments without departing fromthe scope of the present invention.

The invention claimed is:
 1. A suspension element, comprising: a main body having an internal volume; a tubular element extending at least partially within the main body, wherein the tubular element has an internal volume that defines a first fluid chamber, and wherein the main body and the tubular element each include a sidewall having an inner surface and an outer surface; a first piston assembly separating the internal volume of the main body into a second fluid chamber and a third fluid chamber, the third fluid chamber defined by at least portions of the outer surface of the tubular element, the inner surface of the main body, and a surface of the first piston assembly; a second piston assembly positioned to separate the first fluid chamber from the second fluid chamber, the second piston assembly including a first side that is directly exposed to the first fluid chamber and a second side that is directly exposed to the second fluid chamber; and at least one flow control element disposed along a flow path between the second fluid chamber and the third fluid chamber and configured to permit flow therethrough in both a first direction and an opposing second direction, wherein the sidewall of the main body defines an aperture therethrough that forms a portion of the flow path, and wherein the first piston assembly is configured to prevent direct fluid communication between the second fluid chamber and the third fluid chamber during an extension and a contraction of the tubular element.
 2. The suspension element of claim 1, wherein the first piston assembly couples the tubular element to the main body.
 3. The suspension element of claim 1, wherein the first piston assembly extends between the tubular element and the inner surface of the main body.
 4. The suspension element of claim 3, further comprising a cap disposed over a first end of the main body.
 5. The suspension element of claim 4, further comprising a barrier coupled to a second end of the main body, wherein the barrier is annular and includes an aperture configured to receive the sidewall of the tubular element therethrough.
 6. The suspension element of claim 5, wherein the cap defines an aperture in fluid communication with the second fluid chamber and the third fluid chamber.
 7. The suspension element of claim 6, wherein the at least one flow control element is integrated into the cap.
 8. The suspension element of claim 6, wherein the at least one flow control element is coupled to the main body.
 9. The suspension element of claim 5, further comprising a manifold defining a passage that couples the second fluid chamber with the third fluid chamber, wherein the manifold defines at least a portion of the flow path.
 10. The suspension element of claim 9, wherein the manifold comprises a second tubular element, and wherein the sidewall of the main body is disposed at least partially within the second tubular element.
 11. The suspension element of claim 1, wherein the second fluid chamber and the third fluid chamber comprise hydraulic chambers configured to contain a hydraulic fluid therein.
 12. A suspension assembly, comprising: a wheel end assembly; an upper support arm coupled to the wheel end assembly; a lower support arm coupled to the wheel end assembly; a suspension element coupled to at least one of the upper support arm and the lower support arm, the suspension element comprising: a main body having an internal volume; a tubular element extending at least partially within the main body, wherein the tubular element has an internal volume that defines a first fluid chamber, and wherein the main body and the tubular element each include a sidewall having an inner surface and an outer surface; a first piston assembly separating the internal volume of the main body into a second fluid chamber and a third fluid chamber, the third fluid chamber defined by at least portions of the outer surface of the tubular element, the inner surface of the main body, and a surface of the first piston assembly; a second piston assembly positioned to separate the first fluid chamber from the second fluid chamber, the second piston assembly including a first side that is directly exposed to the first fluid chamber and a second side that is directly exposed to the second fluid chamber; and at least one flow control element disposed along a flow path between the second fluid chamber and the third fluid chamber and configured to permit flow therethrough in both a first direction and an opposing second direction, wherein the sidewall of the main body defines an aperture therethrough that forms a portion of the flow path, and wherein the first piston assembly is configured to prevent direct fluid communication between the second fluid chamber and the third fluid chamber during an extension and a contraction of the tubular element.
 13. The suspension assembly of claim 12, wherein the first piston assembly couples the tubular element to the main body.
 14. The suspension assembly of claim 12, wherein the first piston assembly extends between the tubular element and the inner surface of the main body.
 15. The suspension assembly of claim 12, further comprising a cap disposed over a first end of the main body.
 16. The suspension assembly of claim 15, wherein the at least one flow control element is integrated into the cap.
 17. The suspension assembly of claim 12, wherein the second fluid chamber and the third fluid chamber comprise hydraulic chambers configured to contain a hydraulic fluid therein. 